Motor grader blade construction



July 5, 1966 M. E. BEYERs 3,258,864

MOTOR GRADER BLADE CONSTRUCTION Filed March 9, 1964 E 1 E l- I NVENTOR. MqRl//A/EBEyE/Qs ATTORNEYS United States Patent O 3,258,864 MOTGR GRADER BLADE CNSTRUCTION Marvin E. Beyers, Peoria, Ill., assignor to Caterpillar Tractor Co., Peoria, Ill., a corporation of California Filed Mar. 9, 1964, Ser. No. 350,157 2 Claims. (Cl. 37-156) This invention relates to motor grader blade construction and particularly to means associated with a conventional type of blade to improve its operation and the peration of the motor grader itself.

Motor graders, being rubber tired machines, are limited in speed in many grading operations because of bounce lcaused by the tires. Furthermore the conventional blade has limited capacity for pushing earth so in grading operations where it is called upon to till voids or pits, the quantity of earth infront of the blade is often inadequate and two or more passes must be made to fill a relatively small pit. Another disadvantage is the characteristic windrow or berm of earth left by the conventional blade which also necessitates one or more additional passes to complete a grade.

It is an object of the present invention to overcome the above disadvantages and to provide a motor ygrader blade which enables graders to operate at high speeds and at the same time to accomplish a superior levelling or grading job.

Further and more specific objects and advantages of the invention and the manner in which it is carried into practice are made apparent in the following specification wherein reference is made to the accompanying drawing.

In the drawing:

FIG. l is a view in side elevation of a motor grader having a blade embodying the present invention with por- Itions of the blade shown in section;

FIG. 2 is a fragmentary perspective view of the blade circle and blade on the motor grader in FIG. 1; and

FIG. 3 is an enlarged view in side elevation of a slightly modified form of blade with parts broken away and parts shown in section.

The motor grader, generally indicated at in FIG. l of the drawing, has a conventional drawbar 11 and blade circle 12 from which a blade 13 is suspended by a support bracket assembly, generally indicated at 14. A blade support member 34 is pivoted to draft arms 35 of which there are two supported by the blade circle as shown in FIG. 3. They are pivoted by pins 36 and the blade is connected with the members 34 by a common bracket 37 to which the blade and supports are both welded. Pitch adjustment of the blade is accomplished by rotation about the pins 36. Cap screws 38 extend through arcuate slots 39 -in the members 34 and are threaded into the draft arms 3S to retain the blade in its adjusted position. Raising, lowering and tilting of the blade is accomplished through power actuated lift links 15 controlled from the operators station through control mechanism 16, all in a conventional manner.

The blade of the presen-t invention differs from the conventional blade in that it is provided with forwardly extending end wings 18 (see FIG. 2) between the forward ends of which there is a cutting edge 19. This bottomless box-like structure is supported forwardly by a cross beam 20 extending between the upper forward corners of the end wings 18 and supported with respect to the forward portion of the blade circle 12 by an adjusting screw 22. The blade or moldboard portion 13 has a hardened edge 24 used as a striker blade for material cut from the surface being graded by the blade 19 and carried in the bottomless box-like structure in the `manner shown in FIG. 1

where -this earth is illustrated at 25.

In operation, the adjusting screw 22 and lift arms 15 ICC are set to place the forward cutting edge 19 just below the surface of the earth and slightly lower than the elevation of the striker blade 24. Earth may be gathered in a fairly large quantity in the bottomless box-like structure and carried forwardly with the movement of the machine while the striker blade 24 acts, as shown in FIG. 1, to product a level surface regardless of existing voids or pits in the surface to be graded. A larger quantity of earth can be moved and spilling at the forward edges of the end members 18 is avoided by extending the end members a substantial distance forwardly of the cutting blade 19. For deeper cuts, the forward lower edges of the end members are protected by 4hardened bits shown at 27.

The slightly modified assembly as shown in FIG. 3 will be described with the same reference characters primed. The construction of FIG. 3 is different from that of FIG. 2 principally in that the forward portions of the end members 18 extend to a somewhat greater height and are spanned by an I beam 20' in place of the hollow beam 20 (FIG. 2). This enables a somewhat greater range of adjustment by means of a modied screw assembly shown at 22. The screw 22 is retained in a U-shaped member 40 secured to the forward edge of the blade circle and is threaded through a nut 41 xed to the I- beam 20. Consequently, upon turning of the screw the forward portion of the blade structure and the cutting edge can be raised or lowered.

In addition to carrying an exceptionally large quantity of earth before the blade moldboard 13 without spilling it in windrows and the ability to till lar-ge pits in the terrain in a single pass, the weight of earth carried in front of the blade and its frictional contact with the moldboard and with the end members 18 suppresses bounce otherwise induced by operation on rubber tires. In fact in actual operation, it has been shown that a motor grader with the blade of the present invention -is capable of operation at 9 to l0 miles per hour in fourth gear under the same conditions where a standard blade is operated at no greater than four miles per hour in second gear. The elimination of bounce which -makes this possible also minimizes danger and discomfort to the operator and decreases stresses on the machine in general.

I claim:

1. A motor grader blade structure adapted to be secured to a grader blade circle comprising a moldboard with a striker blade thereon, walls extending forwardly from opposite ends of the moldboard, a cutting blade extending between said walls slightly to the rear of the lower forward edges thereof, a cross beam spanning the upper forward edge portions of said walls, said cross beam lying in a vertical plane approximately tangent to the leading yportion of said blade circle vertical adjusting means between the beam and the blade circle and rigidly holding said cross beam against vertical movement and pivot means supporting the moldboard to permit adjustment of blade depth with respect to the ground.

2. The structure of claim 1 in which hardened bits are secured to the forward lower edges of said walls to protect them during deep cuts.

References Cited by the Examiner UNITED STATES PATENTS 1,412,804 4/1922 Gambee 37--42 1,466,464 8/1923 Beatty 37--143 2,141,690 12/1938 Glenn 37-169 2,799,099 7/1957 Leliter 37-156 3,121,964 2/1964 Cobb 37--143 ABRAHAM G. STONE, Primary Examiner.

J. O. BOLT, Assistant Examiner. 

1. A MOTOR GRADER BLADE STURTURE ADAPTED TO BE SECURED TO A GRADER BLADE CIRCLE COMPRISING A MOLDBOARD WITH A STRIKER BLADE THEREON, WALLS EXTENDING FORWARDLY FROM OPPOSITE ENDS OF THE MOLDBOARD, A CUTTING BLADE EXTENDING BETWEEN SAID WALLS SLIGHTLY TO THE REAR OF THE LOWER FORWARD EDGES THEREOF, A CROSS BEAM SPANNING THE UPPER FORWARD EDGE PORTIONS OF SAID WALLS, SAID CROSS BEAM LYING IN A VERTICAL PLANE APPROXIMATELY TANGENT TO THE LEADING PORTION OF SAID BLADE CIRCLE VERTICAL ADJUSTING MEANS BETWEEN THE BEAM AND THE BLADE CIRCLE AND RIGIDLY HOLDING SAID CROSS BEAM AGAINST VERTICAL MOVEMENT AND PIVOT MEANS SUPPORTING THE MOLDBOARD TO PERMIT ADJUSTMENT OF BLADE DEPTH WITH RESPECT TO THE GROUND. 